Hearthstone's first expansion builds on the rivalry between goblins and gnomes

The first expansion for Blizzard's free-to-play digital trading card game Hearthstone: Heroes of Warcraft, called Goblins vs Gnomes, is now available to players. Focusing on the rivalry between Warcraft's two inventor races, the Goblins of Undermine and the Gnomes of Gnomeregan, the update comes with 120 new cards, new Mech minion types and more. As an added bonus, everyone logging on until December 19 will get three free packs of the new cards.

Here's a look at all that's on offer in Goblins vs Gnomes:

Over 120 new cards, including new mech subtype

Packs cost the same as existing expert packs (100 in game gold or $2.99 for two packs)

Cards are also craftable

Free arena pass over the weekend gave players chance to sample the selection

Players in the Americas have access to the expansion starting today, December 8, with those in Europe, Korea, Taiwan, and China able to enjoy the update from December 9.